(i) \(\frac{2}{9}, \frac{2}{3}, \frac{8}{21}\)
= We need to arrange these in descending order,
To find which number is greater or smaller, we make their denominators equal.
\(\Rightarrow \frac{2}{9}, \frac{2}{3}, \frac{8}{21} \quad \begin{aligned}&3 \mid 9,3,2,1 \\&3 \mid 3,1,7 \\&7 \mid 1,1,7\end{aligned}\) \(\Rightarrow \frac{2}{9} \times \frac{7}{7}=\frac{14}{63} \quad \frac{1,1,1}{\text { L.C.M }=}\) \(\Rightarrow \frac{2}{3} \times \frac{21}{21}=\frac{42}{63} \quad 3 \times 3 \times 7 \times 1 \times 1 \times 1 \times=63\) \(\Rightarrow \frac{8}{21} \times \frac{3}{3}=\frac{24}{63}\) \(\therefore \frac{14}{63}, \frac{42}{63}, \frac{24}{63}\) \(\therefore\) desceneding order \(=\frac{42}{63}>\frac{24}{63}>\frac{14}{63}\)
(ii) \(\frac{1}{5}, \frac{3}{7}, \frac{7}{10}\)
\(=\) We make their denominators equal, to find the descending order.
$$
\begin{aligned}
&\Rightarrow \frac{1}{5}, \frac{3}{7}, \frac{7}{10} \\
&\Rightarrow \frac{1}{5} \times \frac{14}{14}=\frac{14}{70} \quad \frac{5 \mid 5,7,10}{71,7,2} \\
&\Rightarrow \frac{3}{7} \times \frac{10}{10}=\frac{30}{70} \quad \text { L1,1,2 } \\
&\Rightarrow \frac{7}{10} \times \frac{7}{7}=\frac{49}{70} \quad \text { L.M } 2 \times 1 \times 1 \times 1=70 \\
&\Rightarrow \frac{14}{70}, \frac{30}{70}, \frac{49}{70} \\
&\therefore \text { desceneding order }=\frac{49}{70}>\frac{30}{70}>\frac{14}{70}
\end{aligned}
$$
